Monitor for automobile

ABSTRACT

A monitor ( 100 ) used in an automobile includes an image sensor ( 10 ), a visual field adjustor ( 20 ) and a display ( 30 ). The image sensing module is secured on the automobile. The visual field adjustor is installed on an incident light path of the image sensing module. The display is electronically connected with the image sensing module and mounted to the automobile.

FIELD OF THE INVENTION

The present invention generally relates to monitors, and moreparticularly relates to a monitor that has a large visual field.

DESCRIPTION OF RELATED ART

Nowadays automobiles are often provided with a monitor secured in thetail thereof to cover the blind spots of their rearview mirrors.Generally, the visual angle of the monitor is designed to be about 60degrees. Because the monitor is secured in the automobile, this visualangle is usually too limited to allow safe driving of the automobile.For example, when the automobile reversing, a driver can only seeobjects in a range covering a visual angle of about 30 degrees to leftand right in which the automobile is reversing, thus increasing thepossibility of an accident. Monitors provided with a visual angle ofmore than 60 degrees can be used to extend the visual field of thedriver, but these monitors require expensive optical components such ascomponents with high refractive index or low dispersive power, thusthese monitors tend to be more complicated and more expensive.

What is needed, therefore, is a simple and inexpensive monitor having alarge visual field to overcome above-described problems.

SUMMARY OF THE INVENTION

In a preferred embodiment thereof, a monitor used in an automobileincludes an image sensor, a visual field adjustor and a display. Theimage sensing module is secured on the automobile. The visual fieldadjustor is installed on an incident light path of the image sensingmodule. The display is electronically connected with the image sensingmodule and mounted to the automobile.

Other advantages and novel features will become more apparent from thefollowing detailed description when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the monitor can be better understood with reference tothe following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present monitor. Moreover, inthe drawings, like reference numerals designate corresponding partsthrough-out the several views.

FIG. 1 is a schematic view of a monitor in accordance with a firstembodiment of the present invention;

FIG. 2 is a schematic view of the monitor receiving an optical imagesignal with an inclination angle to an optical axis of an image sensingmodule shown in FIG. 1;

FIG. 3 is a schematic view of the monitor in a use state shown in FIG.1;

FIG. 4 is a schematic view of a monitor in accordance with a secondembodiment of the present invention; and

FIG. 5 is a schematic view of the monitor shown in FIG. 4 in use.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, FIG. 1 shows a monitor 100 used in anautomobile (not shown) according to a first embodiment of the presentinvention. Additionally, the monitor 100 can be used in other vehiclesand also in fixed installations. The monitor 100 includes an imagesensing module 10, a visual field adjustor 20 and a display 30. Theimage sensing module 10 is installed in the automobile for receivingoptical image signals. An optical axis of the image sensing module 10points to the rear of the automobile. The visual field adjustor 20 isinstalled on an incident light path of the image sensing module 10 toadjust the visual field of the monitor 100. The display 30 iselectronically connected with the image sensing module 10 and is mountedto the automobile for processing and displaying image signals receivedby the image sensing module 10 to a driver of the automobile.

The image sensing module 10 includes an image sensor 11 and a lensmodule 12. The image sensor 11 is a charge coupled device (CCD) imagesensor or a complementary metal oxide semiconductor (CMOS) image sensor.The image sensor 11 is secured on an emitting light path of the lensmodule 12 and electronically connected with the display 30. Opticalimage signals received by the lens module 12 and arriving at the imagesensor 11 are transformed into electronic image signals by the imagesensor 11. The electronic image signals are transferred to the display30 to be displayed. The lens module 12 is installed in the automobileand has a visual angle of 60 degrees.

Also referring to FIG. 2, the visual field adjustor 20 includes a mirror21 and an axis 22. The mirror 21 is a thin planar mirror that includestwo parallel reflectors (not labeled). The mirror 21 is rotatablyinstalled on an incident light path of the lens module 12, and opticalimage signals reflected by the mirror 21 are received by the lens module12. One end of the axis 22 is secured on the midpoint of one side of themirror 21. The other end of the axis 22 is driven by a motor (not shown)installed in the automobile to rotate, thus the mirror 21 is also drivento rotate. Speed of rotating the axis 22 and the mirror 21 is at least50 revolutions per second. In other words, a cycle of rotation of theaxis 22 and the mirror 21 is equal to or less than 0.02 seconds.

According to the laws of reflection, if the mirror 21 and the opticalaxis (the line OZ shown as FIG. 2) of the image sensing module 10 forman angle of n degrees, an optical image signal with an inclination angleof 2n degrees to an optical axis of the image sensing module 10 isreflected to travel along the optical axis and received by the imagesensor 11. Therefore rotating the mirror 21 through an angle of ndegrees results in an effect equal to rotating the image sensing module10 through an angle of 2n degrees. In this way, if the mirror 21 isrotated through an angle of n degrees from a place where the mirror 21and the optical axis of the image sensing module 10 form an angle of 0degrees, the visual field of the monitor 100 is correspondingly rotatedthrough an angle of 2n degrees. Because the lens module 12 has a visualangle of 60 degrees, it receives optical image signals in a rangecovering a visual angle of 30 degrees to left or right according to thedirection in which the automobile is reversing. If the mirror 21 isrotated through an angle of 30 degrees from the place where the mirror21 and the optical axis form an angle of 0 degrees, the visual field ofthe monitor 100 is correspondingly rotated through an angle of 60degrees, thus the visual field of the monitor 100 covers a visual angleof 30 to 90 degrees according to the direction in which the automobileis reversing.

Referring to FIG. 3, when using of the monitor 100, the motor drives themirror 21 to rotate. When the mirror 21 rotates to a first place wherethe mirror 21 and the optical axis of the image sensing module 10 forman angle of 30 degrees in one side, optical image signals in a rangecovering a visual angle of 30 to 90 degrees to one side according to thedirection in which the automobile is reversing are reflected into thevisual field of the lens module 12 by the mirror 21. When the mirror 21rotates from the first place to a second place where the mirror 21 andthe optical axis form an angle of0 degrees, the mirror 21 can not shieldthe lens module 12 because it is very thin, thus the lens module 12receives optical image signals in a range covering a visual angle of 30degrees in left or right according to the direction in which theautomobile is reversing. When the mirror 21 rotates to a third placewhere the mirror 21 and the optical axis form an angle of 30 degrees inanother side, optical image signals in a range covering a visual angleof 30 to 90 degrees in another side according to the direction in whichthe automobile is reversing are reflected into the visual field of thelens module 12 by the mirror 21.

The optical image signals coming from above three positions all coveringa visual angle of 60 degrees are received by the lens module 12, andarrive at the image sensor 11. The image sensor 11 transforms theoptical image signals into electronic image signals and transfers theelectronic image signals to the display 30. The display 30 transformsthe electronic image signals into a panoramic image covering a visualangle of 180 degrees behind the automobile. As the rotation cycle of themirror 21 is not more than 0.02 seconds, i.e. less than the time ofvisual persistence. Before a panoramic image disappears displayed on thedisplay 30 in the driver's eyes, it is replaced by another panoramicimage that comes from the optical image signals received by the lensmodule 12 after the mirror 21 rotates. In this way, changing of thepanoramic images caused by rotating the mirror 21 can-not be sensed bythe driver's eyes. Therefore the driver sees that the panoramic imagescovering a visual angle of 180 degrees behind the automobile arecontinuously displayed on the display 30.

Referring FIG. 4 and FIG. 5, a monitor 200 according to a secondembodiment is provided. All components of the monitor 200 are similar tothe monitor 100 except that the mirror 21 of the monitor 100 is replacedby a prism 41. The prism 41 is movably installed in the incident lightpath of the lens module 12. The prism 41 is made from transparentmaterials such as glass and includes a trapeziform bottom (not labeled),a first side 411, a second side 412, a third side 413 and a fourth side414. The first side 411 is parallel to the second side 412 and the areaof the first side 411 is larger than the area of the second side 412.The third side 413 and the fourth side 414 both intersect with the firstside 411 and the second side 412. The third side 413 and the fourth side414 both form an angle of 60 degrees to the first side 411. Tworeflectors (not shown) are respectively installed on the third side 413and the fourth side 414. The second side 412 is located between thefirst side 411 and the lens module 12. The prism 41 is driven by a motor(not shown) installed in the automobile to move back and forth. A cycleof moving the prism 41 is equal to or less than 0.02 seconds.

In use of the monitor 200, the motor is turned on to drive the prism 41move back and forth. When the prism 41 moves to a first place where thethird side 413 is located in an incident light path of the lens module12, optical image signals in a range covering a visual angle of 30 to 90degrees in one side according to the direction in which the automobileis reversing are reflected into the visual field of the lens module 12by the reflector on the third side 413. When the prism 41 moves from thefirst place to a second place where the second side 412 is located inthe incident light path of the lens module 12, optical image signals ina range covering a visual angle of 30 degrees in left or right accordingto the direction in which the automobile is reversing travel through thefirst side 411 and the second side 412, then the lens module 12 receivesthe optical image signals. When the prism 41 moves to a third placewhere the fourth side 414 is located in the incident light path of thelens module 12, optical image signals in a range covering a visual angleof 30 to 90 degrees in another side according to the direction in whichthe automobile is reversing are reflected into the visual field of thelens module 12 by the reflector on the fourth side 414.

The optical image signals coming from above three positions all coveringa visual angle of 60 degrees are received by the lens module 12, andarrive at the image sensor 11. The image sensor 11 transforms theoptical image signals into electronic image signals and transfers theelectronic image signals to the display 30. The display 30 transformsthe electronic image signals into a panoramic image covering a visualangle of 180 degrees behind the automobile. A moving cycle of the prism41 is not more than 0.02 seconds, i.e. less than the time of visualpersistence. Before a panoramic image disappears displayed on thedisplay 30 in the driver's eyes, it is replaced by a next panoramicimage that comes from the optical image signals received by the lensmodule 12 after the prism 41 moves back and forth. In this way, changingof the panoramic images caused by rotating the mirror 21 can not besensed by the driver's eyes. Therefore the driver sees that thepanoramic images covering a visual angle of 180 degrees behind theautomobile are continuously displayed on the display 30.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setforth in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size, and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. A monitor used in an automobile, comprising: an image sensing modulesecured on the automobile; a visual field adjustor installed on anincident light path of the image sensing module; and a displayelectronically connected with the image sensing module and mounted tothe automobile.
 2. The monitor as claimed in claim 1, wherein the imagesensing module includes a lens module and an image sensor, the imagesensor is secured on an emitting light path of the lens module, and thedisplay is electronically connected with the image sensor.
 3. Themonitor as claimed in claim 2, wherein the visual field adjustorincludes a mirror, the mirror is rotatably installed on an incidentlight path of the lens module and includes two parallel reflectors. 4.The monitor as claimed in claim 3, wherein a cycle of rotating themirror is equal to or less than 0.02 seconds.
 5. The monitor as claimedin claim 2, wherein the visual field adjustor includes a prism made fromtransparent materials, and the prism is movably installed in theincident light path of the lens module.
 6. The monitor as claimed inclaim 5, wherein a cycle of moving the prism is equal to or less than0.02 seconds.
 7. The monitor as claimed in claim 6, wherein the prismincludes a trapeziform bottom, a first side, a second side, a third sideand a fourth side; the first side is parallel to the second side, thearea of the first side is larger than the area of the second side, thethird side and the fourth side both intersect with the first side andthe second side, and the third side and the fourth side both form anangle of 60 degrees to the first side.
 8. The monitor as claimed inclaim 7, wherein two reflectors are respectively installed on the thirdside and the fourth side.
 9. A monitor used in an automobile,comprising: an image sensing module for receiving image signals; avisual field adjustor adjusting the visual field of the monitor; and adisplay electronically connected with the image sensing module, thedisplay processing and displaying image signals received by the imagesensing module.
 10. The monitor as claimed in claim 9, wherein the imagesensing module includes a lens module and an image sensor, the imagesensor is secured on an emitting light path of the lens module, thedisplay is electronically connected with the image sensor.
 11. Themonitor as claimed in claim 10, wherein the visual field adjustorincludes a mirror, the mirror is rotatably installed on an incidentlight path of the lens module and includes two parallel reflectors. 12.The monitor as claimed in claim 11, wherein a cycle of rotating themirror is equal to or less than 0.02 seconds.
 13. The monitor as claimedin claim 10, wherein the visual field adjustor includes a prism madefrom transparent materials, and the prism is movably installed in theincident light path of the lens module.
 14. The monitor as claimed inclaim 13, wherein a cycle of moving the prism is equal to or less than0.02 seconds.
 15. The monitor as claimed in claim 14, wherein the prismincludes a trapeziform bottom, a first side, a second side, a third sideand a fourth side; the first side is parallel to the second side, thearea of the first side is larger than the area of the second side, thethird side and the fourth side both intersect with the first side andthe second side, and the third side and the fourth side both form anangle of 60 degrees with the first side.
 16. The monitor as claimed inclaim 15, wherein two reflectors are respectively installed on the thirdside and the fourth side.
 17. A monitor used in an automobile,comprising: a visual field adjustor having a reflective surfacerotatable so as to reflect image light; an image sensing moduleconfigured for receiving the image light and output an image signalassociated with the image light; and a display electrically connectedwith the image sensing module for displaying the image output from theimage sensing module.
 18. The monitor as claimed in claim 17, whereinthe visual field adjustor includes a mirror.
 19. The monitor as claimedin claim 17, wherein the visual field adjustor includes a prism havingfirst and second sides, and a reflector is mounted on each of the firstand second sides.